Implementing Cisco IP Routing (CCNP ROUTE, legacy) — Question 351

If device R1 has 1-Gigabit and 10-Gigabit Ethernet interfaces, which command do you enter so that it takes full advantage of OSPF costs?

Answer options

• A. R1(config-router)#auto-cost reference-bandwidth 10000
• B. R1(config-route-map)#set metric 10000000000
• C. R1(config-if)#ip ospf cost 10000000000
• D. R1(config-route-map)#set metric 10000
• E. R1(config-router)#auto-cost reference-bandwidth 10000000000
• F. R1(config-if)#ip ospf cost 10000

Correct answer: E

Explanation

The correct command is E, which sets the reference bandwidth for OSPF to 10,000 Mbps (10-Gigabit). This allows OSPF to correctly calculate costs based on the higher bandwidth interface. The other options either set incorrect metrics or reference bandwidths that do not accommodate the 10-Gigabit interface.